I've seen some weird behavior with it, as well. But I'm fine with it. I visit a single subreddit now and if they destroy the UX I'll only be happier for leaving.
They blocked old.reddit.com unless you are logged in on Monday. I don't have an account on there anymore so that effectively blocks me from the entire platform. Oh well.
I am using it right now and it still works for me. I guess it's a rollout. Someone mentioned cookies, maybe it will stop working when they expire, I am not willing to clean them to find out.